Electrical control systems and control devices therefor



Oct. 4, 1955 J, COURTNEY 2,719,927

ELECTRICAL CONTROL SYSTEMS AND CONTROL DEVICES THEREFOR Filed April 17,1955 Inventor (/mas' Co are TMF) United States Patent-O ELECTRICALCONTROL SYSTEMS AND CONTROL DEVICES THEREFOR James Courtney, Donaghadee,Northern Ireland Application April 17, 1953, Serial No. 349,521 Claimspriority, application Great Britain April 18, 1952 3 Claims. (Cl.307-112) This invention relates to electrical control systems andcontrol devices therefor.

According to the present invention I provide an electrical controlsystem including at least two alternative control points, each controlpoint comprising electromechanical means in circuit with the controlsystem, switch means adapted, when closed, to connect the control systemand the electro-mechanical means with a source of electrical power, and,for the switch means, lock means operable by the electro-mechanicalmeans, when energised, the arrangement being such that, operation of theswitch means at one control point to effect closure of same preventslocking of that switch means and, at each other control point, effectslocking of the switch means in the open position.

Further, according to the present invention 1 provide a control devicefor use in a control system having at least two alternative controlpoints comprising electro-mechanical means adapted to be connected incircuit with the control system, switch means adapted, when closed, toconnect the control system and electro-mechanical device with a sourceof electrical power, and, for the switch, lock means operable by theelectro-mechanical means, when energised, the arrangement being suchthat, when a control device as aforesaid is provided at each controlpoint, operation of one switch means to effect closure of same preventslocking of that switch and, at each other control point, effects lockingof the switch means in the open position.

An embodiment of the invention will now be described, by way of examplewith reference to the accompanying diagrammatic drawing, in which:

Fig. 1 is a plan view of the electrical lay-out at one control point,and

Fig. 2 is a fragmentary plan view showing details of the lock means.

Referring to Fig. l of the drawing, the system at each control pointconsists of a solenoid coil I which is connected in circuit throughleads 2, 3 with two main conductors 4, 5 from which a number of relaydevices (not shown) may be energised. Also, at each control point thereis provided two electrical batteries 6, 7 and a drum type switch 8. Theswitch handle (not shown) has three positions. In the mid-position, thecircuit is open and in either of the other two positions, one on eachside of the mid-position, the circuit is closed, current passing fromone or other of the batteries 6, 7 to the solenoid coil 1 and to theleads 2, 3. This current, of course, passes along the conductors 4, 5 toenergise the solenoid coil at each other control point in the system.The contacts for the switch 8 are indicated generally at 9 and 10 forthe battery 6 and at 11 and 12 for the battery 7. The handle of theswitch 8 is removable only in either of the closed positions of theswitch.

The lock means will now be described with reference to Fig. 2 of thedrawing. The solenoid coil 1 is located below the switch drum, and itsplunger 13 is loosely piv- ICC otally connected intermediate the ends ofan arm 14. The arm 14 is pivotally connected at one end by a pin 15 tothe base of the casing of the switch 8, and adjacent its other end has arecess or slot 16, and the spindle 17 of the switch 8 has a pin 19engageable by the slot 16. The arm 14 is urged to the position shown infull lines against a fixed stop 20 by a spring 21, and is movable to theposition shown in chain-dotted lines in which the slot 16 engages thepin 19, as shown, so that the switch is locked in its open position. Thepositions of the pin 19, when the switch 8 is in either of its closedpositions are indicated at 19A and 19B.

In use, the system is energised from one battery at one control point.When the handle of the switch 8 at this control point is moved to aclosed position, say to select battery 6, the contacts 9, 10 are closed,the solenoid' coil 1 is energised and current passes along theconductors 4, 5 and energises the solenoid coils at each other controlpoint. For convenience, the control point at which the switch has beenclosed will now be referred to as the first control point, and the otherpoint or points as the second control point.

When, as aforesaid, the switch 8 at the first control point is closed toselect battery 6, the pin 19 is rotated on the spindle 17 to theposition 19A (Fig. 2). In this position, it will be seen that, thoughthe arm 14 swings inwards under the action of the plunger 13 when thecoil 1 is energised, the slot 16 cannot engage the pin 19 and thisswitch is not locked. As aforesaid, however, the coil 1 at the secondcontrol point is also energised, the switch being open and the pin 19 inthe position shown in full lines. Thus, the plunger 13 swings the arm 14inwards so that the slot 16 engages the pin 19, and locks the switch atthe second control point in its open position.

When the switch 8 at the first control point is opened, the coils 1 ateach point are de-energised, and the arms 14 are swung and held clear ofthe pin 14 by the springs 21.

It will thus be seen that, at any one time, the system can be controlledonly from one control point, and that when the switch at one controlpoint is closed it is not possible for the switch at any other controlpoint to be operated, so that either accidental or unauthorizedoperation of the additional controls is obviated.

The invention is especially applicable to the feed for the variouscontrols for a train formed by a number of rail cars, and in this casethere is one control point in each powered rail car. At each controlpoint there is a number of different controls for which only oneoperating handle is provided, the present control system being one ofthese and that which is operated first of all, and for this reason thehandle can be removed from the switch in the present invention only whenthe switch is closed.

The control system is, of course, equally applicable to rail cars havingcontrol points at each end and to any number of cars single or dualcontrolled forming a train. Also, in some cases, there may only be onebattery at each control point, in which a switch having only twopositions is used.

Modifications may be made without departing from the scope of theinvention and it is to be clearly understood that the invention is notrestricted to use in rail cars.

I claim:

1. An electrical control system including at least two alternativecontrol points, each control point comprising manually operable switchmeans for the control system, lock means for the switch means, andelectro-mechanical means for operating the lock means, the switch meansbeing in circuit with the electro-mechanical means, with the controlcircuit and with a source of electrical power,

3 and all the electro-mechanical means being connected in parallel withthe control system, whereby, when the switch means at any one selectedcontrol point is closed, the electro-mechanical means at all the controlpoints are energised and operate the lock means which lock theunselected switch means in the open position.

2. An electrical control system as claimed in claim 1, in which lockingof the selected switch means in the closed position is prevented byvirtue of the fact that the lock means comprises two interengageableelements, one of which, when the switch means is closed, is moved to aposition in which it cannot be engaged by the other element.

3. An electrical control system including at least two alternativecontrol points, each control point comprising a manually operable rotaryswitch, lock means for the switch, an electro-mechanical device foroperating the lock means, and an electric battery, the switch being incircuit with the electro-mechanical device, with the control circuit andwith the battery, and all the electro-rneehanical devices beingconnected in parallel with the control system so that, when the switchat any one selected control point is closed, the electromechanicaldevices at all the control points are energised, the lock means at eachcontrol point comprising two locking elements, the first of which iscarried by the spindle of the switch and in the open position of theswitch lies in a position in which it may be engaged by the secondelement when actuated by the electro-rnechanical device and which, whenthe selected switch is closed, is rotated with the spindle of the switchto a position in which it cannot be engaged by said second element ofthe lock means so that when the selected switch is closed it is notlocked while all the other switches in the system are locked in the openposition.

References Cited in the file of this patent UNITED STATES PATENTS

